耐高溫菌在環保和農業之利用

Abstract

由果菜市場蔬果廢棄物和農產廢棄物稻草、稻殼和玉米穗軸堆肥中分離耐高溫菌，選擇生長較快和酵素活性較高之放線菌分離株及高溫酯解菌，接種耐高溫纖維素分解菌及高溫酯解菌處理農產廢棄物和製作生物肥料，比較其對作物生長及土壤性質之影響。耐高溫放線菌分離株56號纖維素分解酵素之作用機制，先由外切型纖維素分解酵素(Avicelase)將結晶型的區域，由非還原端將纖維雙醣切下後，再由內切型纖維素分解酵素(CMCase)從非結晶型區域內部任意打斷β-1,4-葡萄糖?鍵結(β-1,4-glucosidic bond)，最後由分解纖維雙醣的β-葡萄糖?酵素(β-glucosidase)切斷雙醣間的鍵結。放線菌分離株56號其Avicelase 的活性是CMCase的6倍。在製作生物肥料時，分別接種放線菌分離株40號和56號及兩種分離株混合於稻草豬糞生物肥料中，放線菌分離株56號提高生物肥料水份含量和灰份含量優於放線菌分離株40號、混合接種菌株及不接菌的控制組；而接種分離株40號及混合菌株提高生物肥料總氮含量和固定態氮含量則優於其他兩組，接種分離株40號其C/N比下降最多。當於含有油脂之廚餘接種高溫酯解菌時，堆積21天時廚餘處理機A(接種)及B(未接種)苜宿種子發芽率分別為95%及87%，顯示生物肥料中對於抑制種子發芽物質已被微生物代謝成穩定無害狀態，生物肥料進入腐熟狀態，堆積28天時除水分含量外，廚餘處理機A及B之pH、總有機碳、總氮、及C/N比等皆符合垃圾堆肥品質標準，其中接種分離株Brevibacillus borstelensis SH168之廚餘處理機A，堆肥化過程溫度明顯較高且有機碳含量及粗脂肪含量分解率較未接菌廚餘處理機B為高，接種分離株Bv. borstelensis SH168於廚餘處理機可使廚餘處理機中發酵溫度升高，促進有機物質分解。廚餘原料中粗脂肪含量嚴重影響堆肥化進行，接種高溫酯解菌，可加速有機物質分解與提高品質。由上可知，生物肥料製作過程中，接種適當之高溫菌對生物肥料之腐熟有正面成效，具應用上潛力。 Thermo-tolerant microbes were isolated from the biofertilizer and compost of the mixture of vegetable-market waste, rice straw and rice hull at 50oC for the measurements of growth rate and cellulolytic activity. Among them 2 isolates of thermo-tolerant actinomycetes were chosen. In submerged culture, isolate No. 56 had high Avicelase activity at 2nd day, CMCase and filter paper activities at 4th day, and β-glucosidase activity at 5th day. Cellulosic materials were degraded first by Avicelase from the non-reducing end, then by CMCase from the non-crystal region and byβ-glucosidase at cellulobiose. Avicelase activity was 6-fold of CMCase. During 31 days biofertilizer preparation of the mixture of rice straw and hog waste (4:1 w/w), biofertilizer inoculating with isolate No. 56 had high final moisture content and ash content. Biofertilizer inoculating with the mixed cultures (isolates No. 40 and No. 56) and isolate No. 40 had high total nitrogen content and immobilized nitrogen content, while biofertilizer inoculating with isolate No. 40 had low C/N ratio. In the biofertilizer preparation from food wastes with high oil content, inoculation of thermophilic lipolytic Brevibacillus borstelensis had higher temperature, organic carbon and crude fat degradation rates than the control without inoculation. Therefore appropriate inoculation of thermo-tolerant or thermophilic microbes in biofertilizer preparation can reduce the period of maturation and improve the quality of compost.